Final answer:
During high-intensity continuous exercise, blood lactate levels increase due to a higher rate of anaerobic metabolism, leading to lactate buildup. While elevated lactate is associated with fatigue, it's only one of several factors impacting exhaustion and muscle performance.
Step-by-step explanation:
During high-intensity continuous exercise, there is an increase in blood lactate levels. This occurs due to a higher rate of glycolysis process compared to the rate at which tissues can absorb the produced lactate. When the demand for ATP exceeds the oxygen supply to the muscles, anaerobic glycolysis is the immediate source of ATP. This process results in the buildup of lactate. Lactate is a by-product of anaerobic metabolism, and when it accumulates, it can contribute to the onset of fatigue. However, the rise in lactate levels is just one of several factors that can lead to fatigue during intense exercise. Other factors include energy availability, oxygen delivery, and psychological factors. With training, the body can become more efficient at clearing lactate, thereby improving its tolerance to high-intensity exercise.